From Peccatore Sanctuary:

Nao, the vice-president of the public morals committee has one mission--to get Narumi, his junior with the bright blonde hair, to dye it a more sober color. But while Nao is doing his job Narumi manages to kiss him, leaving him confused and flustered. Finally, Narumi agrees to change the color of his hair, but only if Nao agrees to go out with him.

Katsutaka and Kazuomi are seniors with a secret hobby: they love watching a pair of younger boys making love. Katsutaka and Kazuomi have fallen completely in love with Yuki and Kaede, and vow to capture them once they enter high school. That awaited day has finally arrived, but will the two seniors be able to reach their goal? And are Kaede and Yuki really who the seniors imagined them to be?